The subject invention is generally directed to a technique for transferring a hologram assembly from one surface to another surface, and more particularly to a technique for transferring a hologram assembly from one non-planar surface to another non-planar surface.
Hologram assemblies comprised of single or multiple hologram layers are being utilized in a variety of holographic products including, for example, automotive head up displays (HUDs) and eye protection goggles. A consideration with holograms is the difficulty of avoiding distortion to the optical properties of a hologram when transferring a hologram from a surface of a substrate utilized for exposure to a surface of a final substrate, particularly where the surface of the final substrate is curved, including for example spherical surfaces, aspherical surfaces, cylindrical surfaces and complex surfaces having continuous bends. Of course, in some applications it may be possible to directly expose the hologram recording layers of a hologram assembly while such layers are attached to the final substrate, but it would be inconvenient or difficult to do this with many final substrates as a result of factors such as size or lack of rigidity of the final substrate. Moreover, commercially available hologram recording films are typically not readily amenable to application to curved substrates for purposes of exposure, except in the case of cylindrical substrates of relative large diameter.